This invention relates to a manifold which is adapted to receive exhaust anesthetic gases from an anesthesia breathing circuit and which thereafter provides control for the same to be delivered to a vacuum exhaust system.
Due to the potential harmful effects on doctors and other attending personnel in the operating theatre, anesthetic gases are, to the extent possible, eliminated from the atmosphere where such personnel are working. Typical systems include manifolds that may surround normal pop-off valves in the anesthesia breathing circuit and which carry the anesthetic gases that escape when the pop-off valve is open to some exhaust means, such as the normal hospital vacuum system, or to specially installed evacuation systems.
In order to directly connect such manifolds or other exhaust means of anesthesia machines to hospital vacuum systems, it is necessary to have some flow control valve to prevent the vacuum system from affecting the anesthesia breathing circuit pressures, and it is also normal to have some type of reservoirs due to the intermittent nature of the exhaust gas flow. The flow control valve combined with a reservoir means allows a fairly steady flow of anesthetic gases to the vacuum system and evens off the otherwise intermittent high flow and then no flow conditions of the gas from the anesthesia breathing circuit.
Accordingly, there are interposed between the various means of collecting the exhaust anesthetic gases and the vacuum systems, manifolds having valves such as needle valves, and which also contain pressure relief valves to prevent an adverse effect on the anesthesia breathing circuit itself.
One common difficulty in present manifolds is that, due to the sensitive nature of such pressure relief valves, they often encounter sticking and do not function at the proper positive or negative pressure. In the event of sticking, it is generally inconvenient to reach the stuck valve to release the same and may require the need to disassemble individual valves to free the movable valve components in separate positive pressure and negative pressure relief valves.